Electronic mail monitoring

Abstract

An extraction section ( 102 ) extracts user identification information and communication terminal identification information from electronic mails acquired by an acquisition section ( 101 ). Then, a calculation section ( 103 ) calculates a uniqueness number of the communication terminal identification information for each of the extracted user identification information. Then, a verification section ( 104 ) judges whether the uniqueness number of communication terminal identification information for each of the calculated user identification information has exceeded a predetermined threshold. Then, for each case, a notification section ( 105 ) performs predetermined notification to a notification destination set up in advance.

1 . An electronic mail monitoring apparatus comprising:
 an acquisition section for acquiring electronic mails transmitted from communication terminals;   an extraction section for, from the electronic mail acquired by the acquisition section, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   a calculation section for, for each user identification information extracted by the extraction section within a unit time, calculating a uniqueness number of the communication terminal identification information;   a verification section for judging whether the uniqueness number of communication terminal identification information for each of the user identification information calculated by the calculation section has exceeded a predetermined first threshold; and   a notification section for, when the verification section has judged that the uniqueness number of communication terminal identification information for each of the user identification information calculated by the calculation section has exceeded the first threshold, performing predetermined first notification to a notification destination set up in advance.   
     
     
         2 . The electronic mail monitoring apparatus according to  claim 1 , wherein:
 when the verification section has judged that the uniqueness number of communication terminal identification information for each of the user identification information calculated by the calculation section has exceeded the first threshold, the calculation section calculates a uniqueness number of countries or regions on the basis of the communication terminal identification information for each user identification information extracted by the extraction section within a unit time;   the verification section judges whether the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded a predetermined second threshold; and   the notification section does not perform the first notification and, when the verification section has judged that the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded the second threshold, performs predetermined second notification to the notification destination.   
     
     
         3 . The electronic mail monitoring apparatus according to  claim 2 , comprising
 a transmission control section for stopping transmission of electronic mails having a transmission source equal to the user identification information whose uniqueness number of the communication terminal identification information has been judged by the verification section as having exceeded the first threshold or, alternatively, equal to the user identification information whose uniqueness number of countries or regions has been judged by the verification section as having exceeded the second threshold.   
     
     
         4 . The electronic mail monitoring apparatus according to  claim 2 , wherein:
 the acquisition section acquires member identification information of the user having transmitted the electronic mail, from a transmission mail server connected to the electronic mail monitoring apparatus; and   the calculation section calculates the uniqueness number of communication terminal identification information or, alternatively, the uniqueness number of countries or regions, for each of the member identification information.   
     
     
         5 . An electronic mail monitoring apparatus comprising:
 an acquisition section for acquiring electronic mails transmitted from communication terminals;   an extraction section for, from the electronic mail acquired by the acquisition section, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   a calculation section for calculating a uniqueness number of countries or regions corresponding to the communication terminal identification information for each user identification information extracted by the extraction section within a unit time;   a verification section for judging whether the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded a predetermined second threshold; and   a notification section for, when the verification section has judged that the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded the second threshold, performing predetermined second notification to a notification destination set up in advance.   
     
     
         6 . The electronic mail monitoring apparatus according to any one of  claim 1 , wherein
 the extraction section extracts an electronic mail address or member identification information as the user identification information and extracts an IP address as the communication terminal identification information.   
     
     
         7 . A transmission mail server comprising:
 an authentication section for authenticating a user;   a storage section for storing authentication information used for the authentication;   an acquisition section for, when the authentication section has succeeded in authentication of the user by using the authentication information stored in the storage section, acquiring electronic mails transmitted from communication terminals;   an extraction section for extracting user identification information indicating the user having transmitted the electronic mail, from the authentication information and then extracting communication terminal identification information imparted to the communication terminal having transmitted the electronic mail, from the electronic mail acquired by the acquisition section or connection processing with the communication terminal;   a calculation section for, for each user identification information extracted by the extraction section within a unit time, calculating a uniqueness number of the communication terminal identification information;   a verification section for judging whether the uniqueness number of communication terminal identification information for each of the user identification information calculated by the calculation section has exceeded a predetermined first threshold; and   a notification section for, when the verification section has judged that the uniqueness number of communication terminal identification information for each of the user identification information calculated by the calculation section has exceeded the first threshold, performing predetermined first notification to a notification destination set up in advance.   
     
     
         8 . A transmission mail server comprising:
 an authentication section for authenticating a user;   a storage section for storing authentication information used for the authentication;   an acquisition section for, when the authentication section has succeeded in authentication of the user by using the authentication information stored in the storage section, acquiring electronic mails transmitted from communication terminals;   an extraction section for extracting user identification information indicating the user having transmitted the electronic mail, from the authentication information and then extracting communication terminal identification information imparted to the communication terminal having transmitted the electronic mail, from the electronic mail acquired by the acquisition section or connection processing with the communication terminal;   a calculation section for calculating a uniqueness number of countries or regions corresponding to the communication terminal identification information for each user identification information extracted by the extraction section within a unit time;   a verification section for judging whether the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded a predetermined second threshold; and   a notification section for, when the verification section has judged that the uniqueness number of countries or regions for each of the user identification information calculated by the calculation section has exceeded the second threshold, performing predetermined second notification to a notification destination set up in advance.   
     
     
         9 . An electronic mail monitoring method of monitoring electronic mails transmitted from communication terminals, performing:
 the processing of acquiring electronic mails transmitted from the communication terminals;   the processing of, from the acquired electronic mail, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   the processing of, for each of the user identification information extracted within a unit time, calculating a uniqueness number of the communication terminal identification information;   the processing of judging whether the uniqueness number of communication terminal identification information for each of the calculated user identification information has exceeded a predetermined first threshold; and   the processing of, when it has been judged that the uniqueness number of communication terminal identification information for each of the calculated user identification information has exceeded the first threshold, performing predetermined first notification to a notification destination set up in advance.   
     
     
         10 . An electronic mail monitoring method of monitoring electronic mails transmitted from communication terminals, performing:
 the processing of acquiring electronic mails transmitted from the communication terminals;   the processing of, from the acquired electronic mail, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   the processing of calculating a uniqueness number of countries or regions corresponding to the communication terminal identification information for each user identification information extracted within a unit time;   the processing of judging whether the uniqueness number of countries or regions for each of the calculated user identification information has exceeded a predetermined second threshold; and   the processing of, when it has been judged that the uniqueness number of countries or regions for each of the calculated user identification information has exceeded the second threshold, performing predetermined second notification to a notification destination set up in advance.   
     
     
         11 . A program for causing a computer to execute:
 the procedure of acquiring electronic mails transmitted from communication terminals;   the procedure of, from the acquired electronic mail, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   the procedure of, for each of the user identification information extracted within a unit time, calculating a uniqueness number of the communication terminal identification information;   the procedure of judging whether the uniqueness number of communication terminal identification information for each of the calculated user identification information has exceeded a predetermined first threshold; and   the procedure of, when it has been judged that the uniqueness number of communication terminal identification information for each of the calculated user identification information has exceeded the first threshold, performing predetermined first notification to a notification destination set up in advance.   
     
     
         12 . A program for causing a computer to execute:
 the procedure of acquiring electronic mails transmitted from communication terminals;   the procedure of, from the acquired electronic mail, extracting user identification information indicating a user having transmitted the electronic mail and communication terminal identification information imparted to the communication terminal having transmitted the electronic mail;   the procedure of calculating a uniqueness number of countries or regions corresponding to the communication terminal identification information for each user identification information extracted within a unit time;   the procedure of judging whether the uniqueness number of countries or regions for each of the calculated user identification information has exceeded a predetermined second threshold; and   the procedure of, when it has been judged that the uniqueness number of countries or regions for each of the calculated user identification information has exceeded the second threshold, performing predetermined second notification to a notification destination set up in advance.